Method for increasing blood flow in vessels

ABSTRACT

A method of restoring lost blood flow capacity to an artery is disclosed. The artery is enlarged by enlarging the flow path of a plaque-ridden segment of the artery using a plaque-removing instrument. The instrument is introduced through a small arteriotomy located remote from the segment. Next, a vascular lining is inserted through the small arteriotomy to a position co-extensive with the segment where the lining is secured.

This application is a continuation of our co-pending U.S. patentapplication Ser. No. 08/402,789, filed Mar. 13, 1995, which is adivision of U.S. patent application Ser. No. 08/073,002, filed Jun. 7,1993, now U.S. Pat. No. 5,571,169.

FIELD OF THE INVENTION

The present invention relates generally to restoration of flow capacityto occluded and partially occluded vessels, including arteries, and moreparticularly to a procedure by which at least an interior lining is inthe form of a vascular graft placed in an artery as an anti-stenoticmeasure.

BACKGROUND

During the last thirty (30) years the most common technique for treatingarterial stenosis has been surgical construction of a bypass conduitaround the site of the occlusion. Bypass grafting in a symptomaticpatient with a partially or totally occluded or stenotic superficialfemoral artery, using a vein or prosthetic graft, has been the dominanttechnique for arterial reconstruction. Endarterectomy is also performedin some cases.

In the last decade balloon catheter angioplasty of patients with focalstenosis has demonstrated benefit primarily because of its minimalinvasiveness, thereby reducing cost and recovery time. It is, however,limited to short focal stenoses through which the balloon can bepositioned. It has a significant rate of restenosis in longer or diffuselesions, where its use is not indicated. To address these limitationsand to improve the treatment of longer length segments of occlusivedisease, a variety of catheter based laser and mechanical atherectomydevices have recently been developed and studied. The hope has been toobtain the benefits of reducing costs, morbidity, and recovery timeavailable from using less-invasive, catheter-based methods while stillobtaining the overall good patient results comparable to by-passgrafting. Despite these efforts, by-pass grafting has remained thetechnique generally used in clinical practice, due to its superioroverall results compared to the novel catheter-based techniquesheretofore developed. The present invention overcomes or substantiallyalleviates the limitations of previous catheter-based techniques fortreating SFA disease, while obtaining the benefits of proven by-passgrafting techniques.

BRIEF SUMMARY AND OBJECTS OF THE INVENTION

In brief summary, the present invention overcomes or substantiallyalleviates the above-mentioned pre-existing problems. The presentinvention provides for removal of all or nearly all atheroma from withinan arterial segment of any length and then placement of a vasculargraft, which may be of any suitable material, with only one point ofentry. The atheroma alone can be removed or the atheroma and the tunicaintima alone or together with the tunica media of the arterial segmentcan be removed. Other vessels can also be treated and vascularly linedwithout departing from the scope of the invention. The present inventionprovides the benefits of minimally invasive surgery, overcomes orsubstantially alleviates the limitation of recurrent stenosis, andallows treatment of any occlusive lesion regardless of length.

Thus, normal capacity blood flow is provided with no or low probabilityof recurring stenosis. While the present invention has been applied toocclusion in the superficial femoral artery, it is not limited to anyparticular artery diseased by stenosis.

With the foregoing in mind, it is a primary object of the presentinvention to provide an antistenotic method and product by whichsubstantially full blood flow capacity is restored to a wholly orpartially occluded artery.

Another object of importance is the provision of a method and product bywhich an atheroma is removed from an artery and provision is made toprevent or alleviate the likelihood of a later redevelopment of anotheratheroma at the removal site.

A further significant object is to provide a method and product by whichsubstantially full blood flow is surgically restored to a stenoticartery.

Another dominant object is the provision of a method and product whichsubstantially eliminates an atheroma from an artery and eliminates orsignificantly reduces the likelihood of restenosis at the prior atheromasite.

An additional object of substantive importance is the provision forremoval of stenotic deposits from an artery with or without removal ofan interior portion of the artery followed by insertion of a vasculargraft along the length of the removal site as an anti-stenosis measure.

One more object of value is the provision of a method of and product forsubstantially removing stenotic deposits in an artery and substantiallypreventing or alleviating recurrence thereof independent of the arteriallength of the deposits.

An additional paramount object is the provision of a novel method andproduct by which a vessel of a medical patient is lined for the purposeof establishing and/or maintaining full blood flow.

These and other objects and features of the present invention will beapparent from the detailed description taken with reference to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The Figures described briefly below are line drawing schematics,predicated upon the existence and commercial availability of the variousdevices and apparatus as shown therein.

FIG. 1 is a line drawing diagrammatically illustrating in cross-sectiona single arteriotomy in an occluded superficial femoral artery of amedical patient;

FIG. 2A is a line drawing schematically illustrating in cross-section adouble arteriotomy in an occluded superficial femoral artery of amedical patent;

FIG. 2B is a line drawing schematically illustrating in cross-sectionaccess using a hollow needle to a site upstream of an atheroma in asuperficial femoral artery of a patient;

FIG. 3 is a line drawing diagrammatically illustrating in cross-sectionthe atheroma of FIG. 1 with a guide wire extending through the atheroma;

FIG. 4 is a line drawing diagrammatically illustrating in cross-sectionplacement of a dynamic wire guide through the arteriotomy sufficient forthe distal region of the dynamic wire guide to extend completely throughthe atheroma accommodating passage of a guide wire through a lumen inthe dynamic wire guide before the dynamic wire guide is withdrawn;

FIG. 5 is a line drawing diagrammatically illustrating in cross-sectionthe advancement of a dynamic disrupter, over a guide wire for traversingthe stenotic obstruction site in the superficial femoral artery;

FIG. 6 is a line drawing diagrammatically illustrating in cross-sectionthe advancement of a coring catheter along a guide wire spanning theatheroma obstruction in the artery to enlarge the lumen by removal ofplaque;

FIG. 7 is a line drawing diagrammatically illustrating in cross-sectionthe artery showing an expandable cutting catheter or atherotomedisplaceable along the guide wire and expansion of blades of the cutterso as to cut plaque from the atheroma, using as many passes asappropriate with or without flushing or irrigating of the lumen;

FIG. 8 is a line drawing diagrammatically illustrating in cross-sectionremoval of the tunica intima endothelium and tunica media collectivelyfrom an artery at a natural interface of weakness existing between thetunica media and the tunica adventitia;

FIG. 9 is a line drawing diagrammatically illustrating in cross-sectionseparation of a length of the tunica intima endothelium together withthe tunica media from the tunica adventitia along a natural interface ofweakness using a Hall loop;

FIG. 10 is a line drawing diagrammatically illustrating in cross-sectiona vascular graft according to the present invention having collapseresistant characteristics placed in the knee of a patient;

FIG. 11 is a line drawing diagrammatically illustrating in fragmentarycross-section use of a Scanlan Endarsector to separate conjointly alength of the tunica intima endothelium and tunica media from the tunicaadventitia along a natural interface of weakness;

FIG. 12 is a line drawing diagrammatically in cross-section a SimpsonAtherocath performing an atherectomy;

FIG. 13 is a line drawing diagrammatically illustrating in cross-sectionperformance of a balloon angioplasty;

FIG. 14 is a line drawing diagrammatically illustrating in cross-sectionthe performance of an atherectomy using a laser;

FIG. 15 is a line drawing diagrammatically illustrating in cross-sectionperformance in an artery of ultrasound angioplasty;

FIG. 16 is a line drawing diagrammatically illustrating in perspectiveone suitable pre-formed cylindrical or sleeve-shaped vascular graft forlining arteries in accordance with the present invention;

FIG. 17 is a line drawing diagrammatically illustrating in perspective atapered, pre-formed vascular graft for carrying out the presentinvention;

FIG. 18 is a line drawing diagrammatically illustrating in perspective,with parts broken away for clarity, the utilization of a vascular graft,pre-formed and cylindrical or sleeve-shaped in configuration, havinginternal ring reinforcements;

FIG. 19 is a line drawing diagrammatically illustrating in perspective,with parts broken away for clarity, a vascular graft, pre-formed andcylindrical or sleeve-shaped in configuration, having internalhelically-shaped reinforcement, for carrying out the present invention;

FIG. 20 is a line drawing diagrammatically illustrating in perspective abifurcated vascular graft for carrying out the present invention;

FIG. 21 is a line drawing diagrammatically illustrating in perspective avascular graft, pre-formed and cylindrical or sleeve-shaped inconfiguration, having tissue in-growth material along a portion of theexterior surface thereof;

FIG. 22 is a line drawing diagrammatically illustrating in perspective,with a portion broken away for clarity, a vascular graft, pre-formed andcylindrical or sleeve-shaped in configuration, having an expandablestent internally sutured at the distal end thereof in the contractedstate, for carrying out the present invention;

FIG. 23 is a line drawing diagrammatically illustrating in cross-sectionplacement of a dilator/sheath along a guide wire into the artery forplacement of a vascular graft;

FIG. 24 is a line drawing diagrammatically illustrating in cross-sectionthe sheath of FIG. 23 with the distal portion thereof in the arteryafter the dilator has been removed;

FIG. 25 is a line drawing diagrammatically illustrating in elevation avascular graft placement mandrel having a vascular graft attached to themandrel shaft for placement in an artery;

FIG. 26 is a line drawing diagrammatically illustrating in cross-sectionof the vascular graft and the distal end of the mandrel of FIG. 25 beingadvanced into the artery through the sheath of FIG. 24;

FIG. 26A is a cross-section taken along line 26A--26A of FIG. 26;

FIG. 27 is a line drawing diagrammatically illustrating in cross-sectionpartial removal of the sheath of FIG. 25 after the distal end of themandrel shaft and the vascular graft has been placed in the desiredposition in the artery through the sheath, with the graft being held bythe mandrel while the sheath is withdrawn;

FIG. 28 is a line drawing diagrammatically illustrating in cross-sectionthe existence of the vascular graft in the artery after both the sheathand the mandrel have been removed therefrom;

FIG. 29 is a line drawing diagrammatically illustrating in cross-sectiona balloon catheter disposed in the vascular graft after the graft hasbeen positioned as illustrated in FIG. 28;

FIG. 30 is a line drawing diagrammatically illustrating in cross-sectionthe vascular graft firmly contiguous with the inside surface of theartery after the vascular graft has been expanded by use of the ballooncatheter illustrated in FIG. 29 and the balloon catheter but not theguide wire has been removed;

FIG. 31 is a line drawing diagrammatically illustrating in cross-sectionthe disposition of the vascular graft in the artery after all otherparaphernalia has been removed;

FIG. 32 is a line drawing diagrammatically illustrating in cross-sectionthe vascular graft of FIG. 32 linearly disposed within and suturedproximally near the wall of the superficial femoral artery;

FIG. 33 is a line drawing diagrammatically illustrating in cross-sectiongrasping of the distal end of a vascular graft in the treated arteryusing forceps;

FIG. 34 is a line drawing diagrammatically illustrating in cross-sectiona vascular graft, sutured at the distal end thereof to the distal end ofa mandrel both disposed in a treated artery;

FIG. 35 is a line drawing diagrammatically illustrating in cross-sectionplacement of the distal end of a vascular graft in an artery by use of aplacer/suturer;

FIG. 36 is a line drawing diagrammatically illustrating in fragmentarycross-section the securing of both ends of a vascular graft in an arteryusing one or more sutures at each end;

FIG. 37 is a line drawing diagrammatically illustrating in fragmentarycross-section securing of a vascular graft in a treated artery usingstaples at both the distal and proximal ends of the vascular graft;

FIG. 38 is a line drawing diagrammatically illustrating in cross-sectiona vascular graft secured at its distal end in an artery using anexpanded stent;

FIG. 39 is a line drawing diagrammatically illustrating in cross-sectionplacement of a coating on the treated interior surface of an artery toform in place a vascular graft.

FIG. 40 is a line drawing diagrammatically in cross-section a ballooncatheter having the balloon thereof partially inflated within a vasculargraft prior to joint insertion into a treated artery; and

FIG. 41 is a line drawing diagrammatically in cross-section thepartially inflated balloon catheter and vascular graft after placementin a treated artery.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Introduction

The illustrated embodiments demonstrate and are representative ofmethods by which a partially or totally occluded artery or other vesselof a patient is recanalized and the risk of restenosis is substantiallyreduced or eliminated by use of a vascular graft within the treatedartery.

While the present invention may be used in a vessel other than anartery, the primary benefit lies in application to an artery. Arteryflow is either conduit or branch flow. The iliac, femoral, and moredistal arteries are most likely to occlude, either totally or partially.All arteries are strong, durable, three-layer vessels while veins arethin, single layer conduits. The arterial wall layers are, inside out,the tunica intima endothelium (intima), the tunica media (media), andthe tunica adventitia (adventitia). It has been found that in diseasedarteries typically the interface between the adventitia layer and themedia layer becomes a region of naturally occurring weakness. In fact,it has been found that plaque not only accumulates within the lumen ofthe artery but infiltrates both the intima and media causing a tissuebreakdown there.

Removal of the intima and the media from the adventitia and leaving theadventitia of the artery is called an endarterectomy.

The primary cause of artery occlusion is build-up of plaque, the densityof which ranges between very soft to rock-hard calcified deposits.Plaque deposits may form in some arteries and not at all or slightly inother arteries of the same person. A plaque deposit in a specific areaor region of an artery is sometimes called an atheroma.

Under appropriate anesthesia the artery is exposed, clamped, and atleast a single arteriotomy is performed distal to the clamp and proximalto the occlusion. Under some circumstances two arteriotomies areperformed, one upstream and the other downstream of the atheromaalthough a single arteriotomy is preferred. In some situations access tothe artery can be by use of percutaneously placed hollow needle, insteadof by use of an arteriotomy.

In situations where an arteriotomy is the preferred choice, a guide wireis advanced through an upstream arteriotomy until the guide wire extendsbeyond the atheroma. Sometimes a guide wire can be advanced through aclogged artery, but not always. In situations where a guide wire alonecannot cross the atheroma, a dynamic wire guide or a dynamic disrupteris preferably used to centrally loosen and/or displace the centrallydisposed plaque followed by central insertion of the guide wire throughthe hollow interior in the dynamic wire guide or disrupter. Thereafter,the dynamic wire guide or disrupter is removed.

Any technique by which the plaque is severed from the inner wall of theintima is called an atherectomy. Typically, plaque may be so severed bya coring catheter or by using an atherotome having one or moreexpandable blades to accommodate insertion and one or more passesthrough the atheroma, each pass at an increased blade diameter.

Atherectomy devices such as a Simpson Atherocath, an Auth Rotablator, aKensey device, or an Interventional Technologies Transluminal ExtractionCatheter (TEC device) may be used.

In some situations an endarterectomy is the preferred medical choice.For example, an endarterectomy is often best when the disease of theartery is substantially advanced, causing a natural interface ofweakness between the media and the adventitia. A cutting atherotome maybe used to initially cut through the diseased intima and media to theadventitia at the distal end of the site of the endarterectomy creatinga taper at that location followed by advancement in a proximal directionuntil the entire undesired length of intima and media have beenexcavated. Alternatively, the intima and media may be cut radially or ona bevel adjacent both a first and second arteriotomy located above andbelow the atheroma. Ideally, a taper is used at both ends of theendarterectomy where the enlarged lumen produced connects across abeveled tapered to the normal lumen of the artery, both distally andproximally the dispensed material is loosened from the wall using anysuitable instrument, such as a surgical spatula. Forceps may be used tograsp and pull upon a loosened part of the intima and media to beremoved causing the intima and media between the two cuts together withthe atheroma contained therein to be removed from the artery as acylindrical unit.

Alternatively, a Hall loop may be advanced from one arteriotomy to theother after the two above-mentioned cuts have been made. The loop, inthe nature of a piano wire loop held on the end of a staff is positionedat the above-mentioned natural interface of weakness. The loop ispositioned at and displaced along the interface by pushing on the staffuntil the intima, the media, and the atheroma to be removed have beenunitarily severed following which the cylindrical unit may be graspedand removed from the artery using forceps, for example.

Similarly, a Scanlan Endarsector or a cutter having rotating blades maybe used to assist in the performance of the endarterectomy.

In situations where an angioplasty, in whole or in part, is thetreatment of choice, an instrument of expansion is used to enlarge oropen and enlarge the blood flow accommodating lumen at the atheroma.Mechanical instruments, equipment for performing balloon angioplasty,laser instruments, and instrumentation for ultrasound angioplasty may beused to achieve the angioplasty.

Once the plaque has been excavated, steps are taken to line theremaining treated arterial or vessel wall. The resulting lining isherein referred to as a vascular graft. Vascular graft, as used herein,is intended to mean any of the following: 1. conventional and novelartificial grafts made of any material, including but not limited tofabrics such as DACRON, or expanded PTFE Gortex™ thin wall sleevematerial, in any density from very soft and low density to very stiffand high-density, constructed in any shape including straight, tapered,or bifurcated, and which may or may not be reinforced with rings andspirals or other reinforcement, and which may or may not have one ormore expandable stents incorporated into the graft at one or both endsor along its length, 2. natural artery or vein material taken from humanor animal donors, 3. stents, 4. coating applied to the inside of thetreated arterial wall which forms a patent lumen or is biologicallyactive and causes the lining of the vessel or duct to form a patentlumen, and 5. any combination of the foregoing vascular graft options.The exterior of the vascular graft or part of it may and preferably doescomprise tissue in-growth material. Where a pre-formed tubular vasculargraft of synthetic material is used, the material thereof may be andpreferably is dimensionally stable. However, if desired, it may beradially expandable material.

The vascular graft of choice may be introduced into the treated arteryor other vessel in any suitable way including but not limited to use ofa dilator/sheath, placement of the vascular graft upon a mandrel shaftand/or use of long-nose forceps. The distal ends of the tubular graftand the mandrel shaft may be temporarily sutured together or the distalend of the vascular graft sutured together over the mandrel toaccommodate unitary displacement into the vessel, for example through asheath after the dilator has been removed.

Where the material of which the vascular graft is formed is expandableand in tubular or sleeve form, once the sheath has been removed thediametral size of the graft may be enlarged in contiguous relationshipwith the inside arterial surface using a balloon catheter. A ballooncatheter may also be used to bring a folded or partially collapsedvascular graft which is dimensionally stable into contiguous relationwith the interior surface of the remaining artery wall.

The tubular graft may also comprise a biologically inert or biologicallyactive anti-stenotic coating applied directly to the treated area of theremaining arterial inner surface to define a lumen of acceptable bloodflow capacity.

The graft, once correctly positioned and contiguous with the interiorvascular wall, is usually inherently secure against inadvertentmigration within the artery or other vessel due to friction andinfiltration of weeping liquid accumulating on the inside artery wall.It is preferred that the length of the vascular graft be selected tospan beyond all of the treated region of the artery.

One or both ends of the vascular graft may be sutured or surgicallystapled in position on the treated wall to prevent undesireddisplacement or partial or complete collapse under cardiovascularpressure. In particular, the upstream end of a graft placed in an arterymust be secure to prevent a flap of the graft from being pushed, byarterial blood flow, into a position where it occludes, in whole or inpart, the vessel. One or both ends may be held open by one or morestents disposed within the tubular graft. Forceps may be used to hold afree end of the vascular graft while the other end is secured to thevascular wall. Currently, it is preferred to secure the proximal end ofthe tubular vascular graft to the treated vascular wall and to biasdilate the distal end of the tubular vascular graft by use of a ballooncatheter and/or arterial pressure. Where the distal exterior of thesleeve-shaped vascular graft comprises tissue in-growth material, as ispreferred as in-growth occurs it becomes immaterial how the initialdilating bias was achieved.

The Illustrated Embodiments

Reference is now made to the drawings wherein like numerals are used todesignate like parts throughout. While the drawings are specificallydirected toward the removal of an atheroma in the superficial femoralartery, it is to be appreciated that the principles of the presentinvention apply to other arteries as well as to ducts and vessels in thebody other than arteries. Specifically, FIG. 1 illustrates the juncturebetween the common femoral artery and the superficial femoral artery andprofunda femoris artery, respectively located at a site near the groinof a medical patient. FIG. 1 further illustrates the existence of asurgically created arteriotomy 50 providing access to the superficialfemoral artery 52 at a location proximal of an atheroma, generallydesignated 54. The atheroma 54 comprises a centrally located, relativelysoft central plaque portion 56 surrounded by a calcified plaque portion58.

FIG. 2A is similar to FIG. 1 and further illustrates a secondarteriotomy 50' located distal of the atheroma 54, providing a secondaccess site to the artery 52, as explained herein in greater detail.

FIG. 2B illustrates the same artery 52 to which access is providedsolely by percutaneous placement of a needle 60 into the hollow of theartery 52 upstream (proximal) of the atheroma 54. Needle 60 accommodatesplaque removal and placement of a lining within the artery 52.

While FIGS. 1, 2A, and 2B illustrate an atheroma which completelyoccludes the artery 52, it is to be appreciated that the presentinvention applies to both partial and complete occlusion due to plaque.The overall objective is to restore substantially full blood flow to theartery and prevent restenosis. It is to be appreciated that the arteryreceiving treatment is temporarily deprived of blood flow altogether,using known methods of temporary occlusion. Prior to temporaryocclusion, systemic or regional heparinization may be effected.

Typically, as illustrated in FIG. 3, after the arteriotomy 50 has beenmade near the origin of the superficial femoral artery, a guide wire 62,conventional in construction, is advanced distally through thearteriotomy 50 and through the atheroma 54 along the softer plaqueportion 56 thereof. If the guide wire 62 alone cannot be manually causedto traverse the atheroma 54, as illustrated in FIG. 3, other medicalinstruments may be used to create a passageway through the atheroma 54following which the guide wire 62 may be appropriately inserted so as totraverse the atheroma 54. For example, a dynamic wire guide 64 may beadvanced and operated so as to create a lumen through the softer plaque56 of the atheroma 54 as diagrammatically illustrated in FIG. 4.Currently, the preferred dynamic wire guide is the one disclosed inpending U.S. patent application Ser. No. 07/973,514, filed Nov. 9, 1992,assigned to EndoVascular Instruments, the assignee of the presentapplication, although other dynamic and static wire guides could beused.

Once the dynamic wire guide 64 has penetrated the central plaque region56 so as to traverse the hard plaque portion 58, the guide wire 62 isadvanced through the lumen within the dynamic wire guide 64, followingwhich the dynamic wire guide is withdrawn leaving the guide wire 62 inposition, as a guide for instruments by which the soft and hard plaque56 and 58 are removed.

Alternatively, with reference to FIG. 5, a dynamic disrupter 66, havinga rotating enlarged rounded tip 67, may be used in lieu of the dynamicwire guide described above to penetrate the softer plaque region 56sufficient to accommodate concentric insertion of the guide wire 62through the dynamic disrupter 66, with the dynamic disrupter 66 afterbeing removed along the guide wire while the guide wire is retained inits inserted position. Currently, the preferred dynamic disrupter is theone disclosed in pending U.S. patent application Ser. No. 07/973,514,filed Nov. 9, 1992, assigned to EndoVascular Instruments, the assigneeof the present application, although other dynamic disrupters could beused.

While not shown, it is to be appreciated that plaque, separated from theatheroma 54, cannot be allowed to remain uncollected within the arteryand, therefore, conventional instruments and procedures are usedappropriately downstream of the atheroma 54 to collect and remove alldebris released during treatment of the atheroma 54.

Having established the appropriate placement of guide wire 62 throughthe atheroma 54, the surgeon is in a position to enlarge the arteriallumen at the site of the atheroma 54 by removing plaque 58. Such removalis commonly referred to as an atherectomy. The severing, grinding,cutting, chipping, and abrading of the plaque 58 may be mechanicallyaccomplished by any suitable cutting instrument. Exemplary types areillustrated in FIGS. 6 and 7, respectively. FIG. 6 illustratesdiagrammatically utilization of a coring catheter 70, advanced along theguide wire 62 through the arteriotomy 50 so as to cut the plaque 58 fromthe artery 52 using as many passes along the atheroma 54 as necessary.The coring catheter has a cutting head 72 which is caused to be rotatedby the surgeon. It is currently preferred that the coring catheter 70 bethat which is disclosed in the assignee's co-pending U.S. patentapplication Ser. No. 07/973,514, which was filed Nov. 9, 1992, althoughany suitable coring catheter may be utilized.

Either in conjunction with a coring catheter or in lieu thereof, thelumen across the atheroma 54 can be enlarged using an expandable cutter,having diametrally expandable cutting blades as illustrated in FIG. 7.The expandable cutter 74 is initially advanced along the guide wire 62in an unexpanded state. Expandable cutter 74 has a diametrallyadjustable cutting head 76 which, when expanded and pulled forwardatherectomy 50 will cut or shave the plaque at deposits 58.Alternatively, the expandable cutter may be utilized in a fashion inwhich the expandable cutting blades, when expanded, engage and grab holdof a section of the plaque. When the expandable cutter is pulled, itboth cuts the junction with the remaining distal plaque and allows acylindrical length of the plaque which lies proximal of the cuttingblades to be removed all in one segment. Typically, a plurality ofpasses of the cutting head 76, each with a slightly greater diameter arerequired to completely excavate plaque 58. Currently, it is preferredthat the expandable cutter disclosed in assignee's U.S. Pat. No.5,211,651 be utilized.

Attention is now turned to those situations where an endarterectomy isthe procedure of choice. Specific reference is now made to FIG. 8 whichillustrates, in part, one way in which the intima 100 and the media 102are collectively separated from the adventitia 104 along a naturalinterface of weakness 106, which typically exists in diseased arteries.A first and second arteriotomy 50 and 50' may be made proximal anddistal of the atheroma and a radial or tapered cut at or near eacharteriotomy made through the intima and media layers to the interface106. By loosening a length of the two interior layers 100 and 102 of theartery 52 from the adventitia along the interface 106 at the radial orbeveled cut adjacent the arteriotomy 50, the loosened part is availablefor grasping, using a suitable instrument such as forceps 108illustrated in FIG. 8. By pulling one or more times in the generaldirection of arrow 110 so as to have a substantial axial-component alongthe length of the artery 52, the cut length of intima and media issevered along interface 106 and pulled from the artery througharteriotomy 50.

While not illustrated in all of the Figures (for simplicity ofpresentation), it is to be appreciated that all arteries comprise threelayers, the intima, the media, and the adventitia.

It is to be understood that the distinction between atherectomy andendarterectomy is somewhat arbitrary, as it depends upon whether thematerial being removed consists exclusively of atheroma only, or of acombination of atheroma and material characteristic of the inner liningof the vessel. Pathology analysis of such removed material frequentlyindicates the presence of cells and other material characteristic ofboth plaque and the media and intima, so it is probably most correct torefer to this procedure as an endarterectomy.

In one currently preferred embodiment, an endarterectomy is performedusing the dynamic disrupter and the expandable cutter. The dynamicdisrupter is first advanced over the guide wire both to loosen theplaque and the intima and media along the natural interface of weakness,and to enlarge the channel or lumen through the artery. The dynamicdisrupter may be advanced one or more times. If multiple advances areused, the repeated advancements may be done using the same tip size, orthey may be done using successively larger tip sizes.

After the dynamic disrupter has been used and withdrawn over the guidewire, the expandable cutter is employed to remove the material that hasbeen loosened. With the blades unexpanded, the expandable cutter isadvanced a suitable distance into the atheromatous region, and then theblades expanded. When the expandable cutter is withdrawn, it engages theplaque and arterial lining, and exerts force upon the natural interfaceof weakness. The plaque and arterial lining are withdrawn by theexpandable cutter in the form of a cylindrical plug of material, whichmay be short or long depending upon how far into the plaque the cutteris advanced before it is expanded. After removing the plug of materialfrom the cutter, the blades are returned to the unexpanded position andre-advanced into the artery, this time to a position further than theprevious advancement, so that a new length of atheromatous material canbe engaged. The blades are once again expanded, and a new plug ofmaterial is engaged and withdrawn. By a repeated series of such steps,any desired length of artery may be excavated of its plaque and innerlining. When the final advance to the most distal point is performed,the distal tapered shape that the blades assume when expanded leavesbehind the desired tapered shape as it cuts and removes the final plugof material from the artery. This eliminates any need to make the secondarteriotomy 50', for the purpose of making the distal radial cut, whenthe expandable cutter is employed.

In the alternative, an endarterectomy may be performed using a Hallloop, as diagrammatically illustrated in FIG. 9. Preliminarily, theartery containing the atheroma 54 is accessed, as illustrated in FIG.2A, by first and second arteriotomies 50 and 50'. The first radial orbeveled cut through the intima and media is made, as described above,and the media is severed along interface 106 at one end or the other(usually the upstream, proximal end) for a short distance to allow theloop 110 to be placed at the interface, with the flexible shaft 112extending in the direction of the pull and through the more remotearteriotomy. When power is applied, the loop is caused to oscillate asthe Hall loop is advanced along the interface 106 until completeseverance has occurred, following which forceps may be used to pull theremoved intima and media layers from the artery through the proximalarteriotomy after the second radial or beveled cut through the intimaand media is made, attempting to leave a tapered contour to theremaining material at the distal end of the endarterectomy. The Hallloop is more fully described in U.S. Pat. No. 3,730,185.

The endarterectomy may similarly be performed using a ScanlanEndarsector, as generally illustrated in FIG. 11. It is to beappreciated that the Scanlan Endarsector 114 is a commercially availableinstrument, sold by Scanlan International, Inc., 1 Scanlan Plaza, St.Paul, Minn. 55107, and may be used alone or in conjunction with otherinstruments to perform the endarterectomy. The Scanlan Endarsector 114comprises a handle (not shown) from which an elongated U-shaped shaftextends. By probing with the Scanlan Endarsector along the interface 106adjacent portions of the media 102 and intima 100 which have beenloosened, further loosening occurs until the endarterectomy is completedand the severed artery portion removed.

Reference is now made to FIGS. 12 through 15 which illustrate variousways in which an atherectomy may be performed when that procedure is thetreatment of choice, in whole or in part, for enlarging the blood flowlumen of artery 52 at atheroma site 54.

With specific reference to FIG. 12, there is illustrated a mechanicalinstrument for the performance of an atherectomy, i.e., SimpsonAtherocath, generally designated 116. The atherocath comprises anoutside, hollow shaft 118 through which extends a rotatable inner shaft120 to which a rotating cutter head 122 is non-rotatably attached. Therotating cutting head 122 cuts plaque 58 from the interior of the artery52 as the atherocath is advanced. A balloon 124 is inflated on the sideopposite the cutting head 122 to thereby bring pressure to bear againstthe artery and urge the cutting head firmly against the plaque. At thedistal end of the atherocath is located a chamber 126, which functionsto collect plaque shavings removed by the cutting head 122. Theatherocath 116 is inserted and removed along guide wire 62. The SimpsonAtherocath is commercially available from Devices for VascularIntervention, division of Eli Lilly, 26201 YNEZ Road, Temecula, Calif.92591.

FIG. 13 diagrammatically represents the use of balloon angioplasty toenlarge the lumen of an atheroma-ridden artery. Specifically, a balloon302 of a balloon catheter 300 is advanced along guide wire 62 until itis disposed within the atheroma 54. Using the side port of the ballooncatheter 300, the balloon 302 is expanded, which radially expands theplaque 58. This process ordinarily creates cracks in the plaque, butnevertheless results in an enlarged lumen through the plaque 58although, typically, the plaque 58 is not intentionally removed.

Reference is now made to FIG. 14 which diagrammatically illustrates useof a laser instrument, generally designated 130 to remove plaque 58 fromartery 52. The laser instrument 50 comprises a source 132 of laserenergy. The laser energy is processed along a bundle of optical fibersdisposed within a catheter 134. Laser beams 136 are emitted from theinstrument 130 through a plurality of laser emitters 138. The laserbeams 136 cut plaque from deposits 58 as the distal end of the catheter134 is advanced distally into the plaque 58. The laser instrument 130 isillustrated as being concentrically disposed upon guide wire 62 forinsertion, advancement, and ultimate removal. Thus, an atherectomy maybe performed in accordance with the principles of the present inventionby use of one or more laser beams. A suitable laser instrument is theLaserprobe PLR or Lasercath-PRL, used with the Optilase Laser SourceSystem, all of which are available from Trimedyne, Inc., 1815 EastCarnegie Avenue, Santa Ana, Calif. 92705.

In lieu of the above-mentioned ways for performance of an atherectomy,or in conjunction therewith, ultrasound energy may be used. Specificreference is made to FIG. 15 which illustrates diagrammatically anultrasound instrument, generally designated 140. Instrument 140comprises a source of ultrasound energy, i.e., ultrasound transducer142. Transducer 142 connects via an ultrasound shaft 144 to anultrasound head 146. The ultrasound shaft 144 is substantiallyconcentrically disposed within an ultrasound catheter 148. A guide wireis not used. Release of ultrasound energy from head 146 is caused toimpinge upon plaque 58 fracturing the same progressively, therebyenlarging the blood flow lumen of the artery 52. A suitable ultrasoundinstrument for removal of plaque is the Sonocath, available fromAngiosonics, Wayne, N.J., (201) 305-1770.

Once the interior of the partially or totally occluded artery has beentreated using an appropriate procedure including one or more of theprocedures described above, the present invention includes placement ofa lining or vascular graft so as to extend preferably co-extensivelyalong the full length of the treated portion of the artery. The natureof the vascular graft will vary depending upon the circumstances, theartery in question, the length over which the artery has been treated,and perhaps other factors. The vascular graft may be of any suitablebiologically inert material including, but not limited to, a DACRONsleeve of medical grade fabric, a sleeve of expanded PTFE (such asGOR-TEX® polytetrofluoroethelene vascular graft tubing available fromW.L. Gore and Associates, Inc., Medical Products Division, 1505 N. 4thStreet, Central Dock 3, Flagstaff, Ariz. 86002). Another availablesleeve formed of expanded PTFE is available from IMPRA, Inc., P.O. Box1740, Tempe, Ariz. 85280-1740.

The material may be dimensionally stable or capable of being expanded,for example, using a balloon catheter and/or one or more stents. Forshort lengths, vascular graft 200 (FIG. 16) may be used. Vascular graft200 is illustrated as having blunt ends, is cut to a length commensuratewith the treated artery and comprises exterior and interior surfacesrespectively comprising a uniform diameter along the entire length ofthe vascular graft 200. The wall thickness is also illustrated as beinguniform.

For longer lengths, tapered vascular graft 202 (FIG. 17) may bepreferable, the degree of taper being selected so as to match the taperof the artery subjected to one or more of the treatments describedabove.

In cases where the artery being lined is bifurcated (e.g., comprises abranch from one to two arteries), vascular graft 204 (FIG. 20) may beused, the configuration thereof being adapted to conform specifically tothe nature of the shape, size, and disposition of the branched arterysubjected to treatment. Depending upon the anatomy, vascular graft 204may be straight or tapered or straight in part and tapered in part.

When strength greater than the mere material from which a vascular graftis formed becomes a consideration, the vascular graft may be reinforced,particularly when no expansion thereof is required during placement. Twotypical forms of reinforcement are illustrated in FIGS. 18 and 19,respectively, which depict vascular graft 206 and vascular graft 208,respectively. Vascular graft 206 comprises reinforcement in the form ofa plurality of rings 210. While illustrated as being embedded within thematerial 212 from which the vascular graft 206 is formed, thereinforcing rings could be placed either internally or externally inrespect to the graft 206 itself.

Similarly, vascular graft 208 is illustrated in FIG. 19 as comprising acontinuous, helical reinforcement 214 embedded in the material 216 fromwhich the vascular graft 208 is formed. The reinforcement 214 could beplaced as well either internally or externally of the vascular graft 208itself.

The reinforcement, e.g., rings 210 and helix 24 can be of any suitablebiologically inert material such as an implantable grade ofthermoplastic material, e.g., polypropylene or nylon. Even in caseswhere sutures, staples, and/or stents are used to initially hold thelining or vascular graft contiguously against the treated artery wall,utilization of tissue in-growth material at the exterior of all or partof the vascular graft may be desirable. In this regard, specificreference is made to FIG. 21 which diagrammatically illustrates theexistence of tissue in-growth material 220 disposed along approximatelythe distal one-half of the hollow cylindrically-shaped vascular graft222. The value of the tissue in-growth material is that it becomes, indue course of time, the primary connector between the treated arterialsurface and the vascular graft.

With reference to FIG. 22, there is diagrammatically illustrated ahollow cylindrical vascular graft 224 to which an expandable stent 226has been connected interiorly at the proximal end thereof using sutures228. Once the vascular graft 224 is properly positioned within a treatedartery, the stent 226 is conventionally expanded to bias the proximalend of the vascular graft 224 contiguously against the treated arterialsurface to retain the position of placement. This condition isillustrated in FIG. 38. While illustrated as being placed internallyinside of graft 224, the stent could also be placed externally or itcould be embedded within the material from which the vascular graft 224is formed.

Utilization of a vascular graft within the context of the presentinvention significantly tends to provide a barrier between thebloodstream and the vessel wall which is believed to reduce restenosis,provides a conduit through which the blood can flow which is known to bewell-tolerated by the bloodstream, preserves the area available forblood flow, prevents an aneurysm, promotes rapid healing withoutexcessive weeping or adhesion of blood at the lining site between thevascular graft and the adventitia layer, and provokes minimal scarring.Plaque, it has been determined, does not form on and adhere to thevascular graft.

In lieu of a pre-formed straight or tapered sleeve (with or without abifurcation) the treated arterial wall, e.g., at interface 106, may belined using a liquid coating of suitable material applied as a spray orotherwise and allowed to cure until a hollow lumen is defined within thecured coating and the treated arterial surface is concealed by thecoating, or allowed to remain in place long enough to cause the arteryto form a stable, hollow lumen. In this regard, reference is made toFIG. 39 which illustrates the presence of a manually controlled nozzle230 forming a part of a surgical spraying instrument by which a coating232 is applied to the treated arterial surface at interface 106.Suitable coatings, for example, having the requisite biologically inertcharacteristics and wall adherence characteristics would includepharmaceutical-grade collagen available from Collagen Corp., 1850Embariadero Road, Palo Alto, Calif. 94303.

Once the vascular graft of choice has been selected, other than anin-place coating, insertion of the vascular graft into the treatedartery must be achieved. It is currently preferred to use a commerciallyavailable dilator/peel-away sheath generally designated 250 (FIGS. 23,24, 26, and 27). However, a solid (non-peel-away) sheath may also beutilized or the graft may be inserted directly into the vessel withoutuse of a sheath. As is well known in the art, the dilator/sheath 250, inassembled condition, is passed concentrically along the guide wire 62through the access opening to the artery 52. The access opening may bean arteriotomy 50 or a percutaneous venipuncture caused by insertion ofneedle 60 (FIG. 2B) followed by advancement of the guide wire throughthe needle 60 and subsequent removal of the needle. In the case of aneedle puncture, the dilator 252 at the tapered distal tip 254 enlargesthe radial size of the puncture as does the sheath 256 (slightly) as thedilator-sheath 250 is advanced through the puncture concentricallyaround the guide wire 62 until the dilator-sheath 250 is positioned asillustrated in FIG. 23. Once the position of FIG. 23 has been achieved,the medical attendant simply manually retracts the dilator along theguide wire 62 until it is fully removed, leaving the sheath 256 in placewith the proximal end thereof exposed, as diagrammatically illustratedin FIG. 24.

Next, steps are taken to insert the vascular graft through the sheathand locate the graft in the treated artery so as to be, preferably, atleast co-extensive with the treated artery surface, with the guide wireinside the graft. The treated artery surface shown in FIGS. 23-24 and26-27 is interface 106. One way in which insertion may be consummated isby use of a graft placement long-nose forceps, generally designated 260(FIG. 25) which comprises a control handle 262 from which a mandrelshaft 264 distally extends. Activation of the control 262 causesbifurcated tips 266 located at the distal end of the mandrel shaft 264to open and close, to grasp or clamp and release, respectively, thedistal end 268 of a hollow tubular vascular graft 270. By graspingbetween tips 266 the distal end 268 of the vascular graft 270, thevascular graft follows the mandrel shaft 264 as it is advanced over theguide wire 62 and through the sheath 256 as illustrated in FIGS. 26 and27.

With the graft 270 correctly positioned in the artery 52, the forceps260 and graft 270 are held in a stationary position, the forcepsgrasping the graft, as the sheath is withdrawn. In the case of peel-awaysheath 256, as the sheath is withdrawn it is manually split into twopieces, as illustrated in FIG. 27, following which each piece isdiscarded.

At this point, the forceps 260 and the graft 270, with the guide wire 62passing centrally through the graft, are left in position and the sheath256 has been entirely removed. Thereafter, the guide wire and graft 270are held stationary, the mandrel control 262 manipulated to open thetips 266 causing the distal end 268 of the graft 270 to be released,following which the forceps 260 are withdrawn while the guide wire 62and the graft 270 are retained in position as illustrated in FIG. 28.

Alternatively, the sheath may be placed correctly in the artery 52 usinga hollow mandrel, generally designated 280 (FIG. 34). Wherein the sheath270 is concentrically disposed around the hollow mandrel 280 with thedistal ends of each being sutured together using apertures 282 locatedin the distal end of the mandrel 280. By placing a suture 284 helicallythrough the apertures 282 and through the adjacent thickness of thevascular graft 270, the vascular graft and the mandrel are securedtogether. Where only one access opening, such as arteriotomy 50, isused, the suture 284 may be extended through the hollow of the mandrel280 and through the arteriotomy 50 for access by the medical attendant.Once fully positioned in the artery, one end of the suture 284 is pulledby the medical attendant, causing the suture to helically unwind at thedistal end of the vascular graft 270 for complete removal of the suture284, following which the mandrel 280 is fully retracted leaving thevascular graft 270 correctly disposed in the artery 52, with the guidewire 62 inside the graft.

Similarly, with or without a dilator/sheath, used in the mannerdescribed above, an elongated, long-nose forceps 290 (FIG. 35) may beused as well for correct placement of the vascular graft 270. Long-noseforceps 290 may be of any suitable type, such as commercially availablepediatric bronchoscopy forceps or retrieval forceps, such as Storz's.More specifically, the forceps 290 comprise exposed jaws 292 which arecontrolled at the proximal end of the forceps 290 accommodating openingand closing of the jaws 292. By creasing or folding at 268 the vasculargraft 270 and forcing the crease or fold 268 between the jaws 292 whenopen accommodates clamping of the creased distal end 268 when the jaws292 are tightly closed. Thereafter, the forceps 290 and the vasculargraft 270 are jointly advanced through the access site, such asarteriotomy 50, until the vascular graft 270 is correctly located in thetreated artery 52, as illustrated in FIG. 35. Thereafter, the jaws 292are opened, the fold 268 at the distal end of the vascular graft 270 isreleased and the forceps 290 retracted leaving the vascular graft 270properly disposed within the artery 52.

Independent of the procedure used, the vascular graft 270 is nowcorrectly located in the artery 52, with the guide wire 62 passingthrough the center of the vascular graft 270, as illustrated in FIG. 28.

Insertion of a tubular graft of choice into the treated artery ofteninvolves folding or other forms of reduction in the diametral sizeoccupied by the vascular graft during insertion, for example, toaccommodate a size which will allow displacement through the sheath 256.The sheath handle may accept a graft folded shown in FIG. 26A. Thisfolded configuration may continue the length of the sheath, to allow theeasier passage of the graft through the sheath, by de-forming the insidediameter to the shape, or by laying a conventional catheter or wirealongside the graft during insertion to create an indentation in thegraft. For this reason and because, typically, the walls of a syntheticvascular graft are very supple and lack shape-retaining strength, thevascular graft, if left alone, tends to be and remain non-contiguouswith the treated surface at the interior of the artery, e.g., surface106, e.g., retaining the crimped or folded shape it assumes duringinsertion. In order to provide a contiguous relationship between thevascular graft and the adjacent arterial wall and to dilate the vasculargraft to its full diameter, it is presently preferred that a ballooncatheter 300 of conventional, commercially available design be advancedconcentrically around the guide wire 62 until the balloon 302 thereof ispositioned within the sheath 270 just inside the distal edge 2681 of thesheath 270. See FIG. 29.

By sequentially expanding, deflating, slightly displacing and once moreinflating, etc., the balloon 302, the vascular graft 270 is caused tobecome contiguous with and adhered to the adjacent arterial wallsurface, following which the balloon 302 is deflated and the ballooncatheter 300 retracted along the guide wire and discarded, leaving thevascular graft 270 postured as illustrated in FIG. 30. Alternatively,one very long balloon catheter can be employed to perform this step in asingle balloon expansion, and/or the balloon can be sized to exactlymatch the graft, e.g., tapered balloon used with tapered graft, etc.

Thereafter, the guide wire 62 is fully retracted, leaving the tubularvascular graft 270 positioned as essentially illustrated in FIG. 31. Ithas been found that once the tubular vascular graft is firmly contiguouswith the adjacent arterial wall surface, a measure of friction existswhich both prevents radial collapse and axial displacement of thevascular graft within the artery. In addition, the treated arterialsurface tends to weep slightly which weeping adheres to the exteriorsurface of the tubular graft and tends to infiltrate the material fromwhich the tubular graft is formed at least to a limited extent furthercausing the graft to be retained in its expanded stationary position,fully dilated within the artery.

As best illustrated in FIG. 32, it is presently preferred that only theproximal end 269 of the vascular graft 270 be physically connected tothe adjacent arterial wall, in this case adventitia layer 104, and thatthe distal end 268 be left to natural adherence, with the arterial bloodpressure holding the distal end 268 in its fully dilated positiontogether with friction at the surface 106 and tissue infiltration intothe material from which the graft 270 is fabricated. In FIG. 32 theutilization of one or more sutures 304 is illustrated as the structureby which the proximal end 269 of the vascular graft 270 is physicallysecured to the arterial wall.

Over the longer term, the graft will be held open and contiguous withthe remaining original wall of the artery throughout its length byarterial blood pressure and, in grafts so constructed, by tissuein-growth into the tissue in-growth material. This particular feature ofintra-luminal graft placement solves a specific problem of by-pass graftplacement where by-pass grafts have previously been placed in tissuetunnels constructed to by-pass the original duct or vessel lumen. Manysuch grafts are placed in body regions where, under normal activities,the body tends to compress grafts and thereby cut off flow through suchgrafts when they are placed in tissue tunnels which by-pass the originallumen. The example of the human knee joint is illustrated in FIG. 10.Convention placement of by-pass grafts, which pass through the kneejoint, results in the surrounding tissue tending to compress the graftand cut off flow when the knee is bent. Conventionally, this problem hasbeen solved by using a reinforced graft, as previously illustrated inFIGS. 18 and 19, wherein the reinforcing holds the graft lumen open andpatent when external tissue pressure is exerted on the graft.

An improved result is obtained using the intra-luminal graft placementdescribed herein is illustrated in FIG. 10. The original artery lumenremains open and patent in the knee even when the knee is bent. Moregenerally, ducts and vessels naturally remain open and patent during thenormal range of activities. In FIG. 10, the lumen of the graft, which isadhering to the remaining original wall of the artery by tissuein-growth and/or due to the arterial pressure inside the graft, isillustrated as remaining open and patent even while the knee is bent.More generally, intra-luminal grafts held in place in vessels or ductsby tissue in-growth will remain open and patent during the normal rangeof activities, including activities that tend to obstruct by-pass graftsplaced in tissue tunnels.

While it is currently preferred that the distal end 268 of the vasculargraft 270 be without manmade connection to the vascular wall, if desiredthe distal end 268 may be so secured. Specifically, FIG. 36 illustratesutilization of one or more sutures 304 to secure both the proximal anddistal ends 269 and 268, respectively, of the vascular graft 270 to thearterial wall 104. Placement of sutures 304 at the distal end 268 of thevascular graft 270 would ordinarily require a second, downstreamarteriotomy.

Similarly, one or both ends of the vascular graft 270 may be secured tothe arterial wall 104 using medical grade staples 306, as illustrated inFIG. 37.

Furthermore, either or both ends of the vascular graft 270 can beexpanded and held in contiguous relationship with arterial surface 106using one or more stents 226, as explained above and as illustrated inFIG. 38.

While ordinarily not necessary, the distal end 268 of the vascular graft270 may be grasped using suitable forceps 310 for both positioning thevascular graft 270 and for holding it in position while, for example,the proximal end of the graft is suitably fastened to the arterial wallas explained above. See FIG. 33.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are, therefore, to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:
 1. A lowinvasive method of restoring lost blood flow capacity to an artery of amedical patient, comprising the steps of:enlarging the flow path size ofa plaque-ridden segment of an artery using a plaquere-moving instrumentintroduced through a small arteriotomy located remote from the segment;clamping a vascular lining to a clamping instrument such that the liningis compressively secured by the clamping instrument and at least asubstantial portion of an exterior surface of the lining is exposedapart from the clamping instrument; thereafter jointly inserting theexposed lining and the clamping instrument into the artery through theremote small arteriotomy and thence to a position at least in partco-extensive with a portion of the segment; securing the vascular liningwithin said artery at said position.
 2. A low invasive method accordingto claim 1 wherein the enlarging step comprises enlarging the flow pathwithin the artery by performing plaquere-moving angioplasty remote fromthe small arteriotomy.
 3. A low invasive method according to claim 1wherein the enlarging step comprises first loosening, remote from thesmall arteriotomy, and thereafter removing plaque through the smallremote arteriotomy.
 4. A low invasive method according to claim 1wherein the enlarging step comprises cutting plaque remote from thesmall arteriotomy.
 5. A low invasive method according to claim 1 whereinthe enlarging step comprises chipping plaque remote from the smallarteriotomy.
 6. A low invasive method according to claim 1 wherein theenlarging step comprises grinding plaque remote from the smallarteriotomy.
 7. A low invasive method according to claim 1 wherein theenlarging step comprises applying laser energy to the plaque remote fromthe small arteriotomy.
 8. A low invasive method of restoring lost bloodflow capacity to an artery of a medical patient, comprising the stepsof:providing a small access passageway into the artery; enlarging theflow path size of a plaque-ridden segment of the artery comprisingaxially cutting longitudinally away from the passageway and removingboth plaque and a portion of the interior of the artery through thepassageway; placing a vascular lining into the artery through thepassageway to a location at least in part co-extensive with a portion ofthe segment; securing the vascular lining within said artery at saidlocation.
 9. A low invasive method according to claim 1 wherein theenlarging step comprises applying ultrasound energy to disconnect plaquefrom the segment remote from the small arteriotomy.
 10. A low invasivemethod according to claim 1 wherein the enlarging step comprisesexcising pieces of plaque, obtained at the segment remote from thearteriotomy, from the artery through the small arteriotomy.
 11. A lowinvasive method according to claim 1 wherein the enlarging stepcomprises grasping and tearing pieces of plaque from the artery remotefrom the small arteriotomy.
 12. A low invasive method according to claim1 wherein the enlarging step comprises diametrally expanding theplaque-ridden segment of the artery remote from the small arteriotomy.